1. Field of the Invention
The present invention relates to a connecting unit in the form of an integrated circuit (IC) socket for loading, for example, an IC, and in particular, to a connecting unit including contactors to be put in contact with external connecting portions of, for example, an IC, the contactors having superior electrical conductivity and resilience, and to a method for producing the same.
2. Description of the Related Art
A semiconductor inspecting unit disclosed in Japanese Unexamined Patent Application Publication No. 2002-175859 is used for electrically connecting a semiconductor device to, for example, an external circuit board temporarily. A large number of spherical contactors disposed in a grid or a matrix shape are provided on the back surface of the semiconductor device. An insulating substrate having a large number of holes is disposed facing the semiconductor device. Spiral contactors are disposed in the holes.
When the semiconductor device is pressed toward the insulating substrate, spiral contactors make contact with the external surfaces of the spherical contactors disposed on the back surface of the semiconductor device such that the spiral contactors wind around the spherical contactors. Thus, the spherical contactors and the spiral contactors are reliably connected to each other electrically.
In a known method, the spiral contactors are formed by, for example, pressing. As products become reduced in size, the semiconductor inspecting unit must be electrically connected with a semiconductor device reliably in a fine area. Therefore, the possibility of forming the spiral contactors by pressing is limited. In order to further reduce the size, the spiral contactors must be formed by a new alternative method instead of by pressing.
In addition to further reducing the size, the spiral contactors require superior electrical conductivity and resilience.
With regard to this, Japanese Unexamined Patent Application Publication No. 2002-175859 discloses various methods for forming the spiral contactors in FIGS. 37 to 39.
For example, according to the method disclosed in FIG. 37, spiral contractors are mainly composed of nickel formed by plating. In a fine contact point using such a spiral contactor, however, excessively high conductor resistance leads to failure or impossibility of inspection.
According to the method disclosed in FIG. 38, the spiral contactors include a substrate 63 in addition to a copper foil 4′ and other members. Since this structure decreases the resilience of the spiral contactors, the spiral contactors cannot sufficiently perform elastic deformation depending on the shape of the spherical contactors disposed on the semiconductor device, thereby causing contact failure.
Furthermore, no appropriate improvement in either the electrical conductivity or the resilience of the spiral contactors is mentioned in the above patent document.